feat(Item Lists Node): Split merge binary data (#7297)

Github issue / Community forum post (link here to close automatically):

---------

Co-authored-by: Marcus <marcus@n8n.io>

packages/nodes-base/nodes/ItemLists/V3/helpers/utils.ts

@@ -1,11 +1,12 @@
 import { NodeVM } from '@n8n/vm2';
-import {
-	NodeOperationError,
-	type IDataObject,
-	type IExecuteFunctions,
-	type INode,
-	type INodeExecutionData,
+import type {
+	IDataObject,
+	IExecuteFunctions,
+	IBinaryData,
+	INode,
+	INodeExecutionData,
 } from 'n8n-workflow';
+import { NodeOperationError } from 'n8n-workflow';
 
 import get from 'lodash/get';
 import isEqual from 'lodash/isEqual';
@@ -87,3 +88,62 @@ export function sortByCode(
 
 	return vm.run(`module.exports = items.sort((a, b) => { ${code} })`);
 }
+
+type PartialBinaryData = Omit<IBinaryData, 'data'>;
+const isBinaryUniqueSetup = () => {
+	const binaries: PartialBinaryData[] = [];
+	return (binary: IBinaryData) => {
+		for (const existingBinary of binaries) {
+			if (
+				existingBinary.mimeType === binary.mimeType &&
+				existingBinary.fileType === binary.fileType &&
+				existingBinary.fileSize === binary.fileSize &&
+				existingBinary.fileExtension === binary.fileExtension
+			) {
+				return false;
+			}
+		}
+
+		binaries.push({
+			mimeType: binary.mimeType,
+			fileType: binary.fileType,
+			fileSize: binary.fileSize,
+			fileExtension: binary.fileExtension,
+		});
+
+		return true;
+	};
+};
+
+export function addBinariesToItem(
+	newItem: INodeExecutionData,
+	items: INodeExecutionData[],
+	uniqueOnly?: boolean,
+) {
+	const isBinaryUnique = uniqueOnly ? isBinaryUniqueSetup() : undefined;
+
+	for (const item of items) {
+		if (item.binary === undefined) continue;
+
+		for (const key of Object.keys(item.binary)) {
+			if (!newItem.binary) newItem.binary = {};
+			let binaryKey = key;
+			const binary = item.binary[key];
+
+			if (isBinaryUnique && !isBinaryUnique(binary)) {
+				continue;
+			}
+
+			// If the binary key already exists add a suffix to it
+			let i = 1;
+			while (newItem.binary[binaryKey] !== undefined) {
+				binaryKey = `${key}_${i}`;
+				i++;
+			}
+
+			newItem.binary[binaryKey] = binary;
+		}
+	}
+
+	return newItem;
+}